Wassim Bouhlel, a Nice native who spoke to the Associated Press near Nice’s Promenade du Paillon, said that he saw a truck drive into the crowd and then witnessed the man emerge with a gun and start shooting.

Writing online, Nice Matin journalist Damien Allemand who was at the waterside said the fireworks display had finished and the crowd had got up to leave when they heard a noise and cries.

“A fraction of a second later, an enormous white truck came along at a crazy speed, turning the wheel to mow down the maximum number of people,” he said.

“I saw bodies flying like bowling pins along its route. Heard noises, cries that I will never forget.”

City officials told BFM TV that people should remain indoors.

President Barack Obama has been briefed on the attack.

“On behalf of the American people, I condemn in the strongest terms what appears to be a horrific terrorist attack in Nice,” the president said in a statement, adding that he offered French officials whatever assistance they may need.

“We stand in solidarity and partnership with France, our oldest ally, as they respond to and recover from this attack,” he continued.

Reports of hostages being held nearby and another attack near the Eiffel Tower were not true.

Bastille Day, celebrated by the French on July 14 each year, is equivalent to the American Fourth of July holiday. It celebrates the day that French revolutionists stormed the infamous Bastille prison, which was holding both political opponents of the king and weapons and ammunition needed to overthrow the government.